Email Subject Line Tester

Score subject lines for length, clarity, spam risk, and mobile truncation.

How it works

Type a subject line → click Test → see if it’s okay to send

We’ll check spammy words, length (mobile cut-off), clarity, and shouty formatting — then tell you what’s wrong and what’s fine. Writing helper only; not a guarantee of open rate.

Or start from an example

Results appear here after you click Test subject line.

Ready to send with MailShrine?

New accounts get free signup credits. Fix the subject, then send from MailShrine.